JPH0537903A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain effective slow reproduction by obtaining a reproduced image at the time of executing slow reproduction preventing the mixture of fields and obtaining reproduction control signal corresponding to the image. CONSTITUTION:This magnetic recording/reproducing device for a MUSE signal is provided with a selector 9 to which video signals reproduced by + azimuth heads 1, 4 are inputted at the time of slow reproduction and a selector to which video signals reproduced by-azimuth heads 2, 3 are inputted. Signals from the selectors 9, 10 are switched by a control signal Fp/n corresponding to a slow reproduction speed in a selector 11. A reproduction control signal is changed so as to have phase information corresponding to a reproduced video signal and added to the reproduced video signal.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a MUSE signal (Multiple Sub) recorded by band-compressing a so-called high-definition television (High Definition Television) signal.
-A magnetic recording / reproducing apparatus for reproducing Nyquist Sampling Encoding).

[0002]

2. Description of the Related Art The MUSE system is a band compression system developed by NHK (Japan Broadcasting Corporation) for transmitting high-definition signals by broadcasting satellites, and its content is NHK Technical Research, Showa 62, Vol. 39, Vol. No. 2, pp.18-53, etc.

According to this method, the baseband HDTV signal is band-compressed to 8.1 MHz by performing offset subsampling. In the broadcasting satellite, the data is transmitted with the configuration shown in FIG. That is, one line is sampled at 480 points, 11 points are assigned to HD (horizontal synchronization signal), 94 points are assigned to color difference signal (C signal), and 374 points are assigned to luminance signal (Y signal). And the luminance signal are line-sequentially and time-division multiplexed and transmitted.

Further, as shown in FIG. 10, the sampling phase of each field of the MUSE signal is formed into a sampling pattern, and this sampling phase is cyclic in four fields.

Here, FIG. 11 shows an example of a basic configuration of a MUSE decoder for restoring the MUSE signal into a high-definition baseband signal.

In the MUSE decoder having the configuration shown in FIG. 11, when a MUSE signal is input to the input terminal 31, A
The MUSE signal input by the / D conversion circuit 32 is converted into a digital signal and sent to the de-emphasis circuit 34 and the control signal separation / detection circuit 33. In the de-emphasis circuit 34, a process reverse to the emphasis process performed for transmission is performed and then sent to the moving image processing circuit 37, the still image processing circuit 36, and the motion detection circuit 35, respectively.

In the moving image processing circuit 37, only the interpolation processing in the field is performed to generate a moving image signal, and this moving image signal is sent to the mixing circuit 38. On the other hand, in the still image processing circuit 36, inter-frame interpolation processing is performed after performing inter-frame interpolation processing using signals of four fields. That is, a still image signal is generated using all four types of sample points shown in FIG.
Sent to.

In the motion detection circuit 35, the input MUS
By taking the difference between the 1st. (First) frame and the 2nd. (Second) frame of the E signal, the moving area of the image is detected to generate a motion signal, and the motion signal is sent to the mixing circuit 38.

The control signal separation / detection circuit 3
In 3, the control signal in the input MUSE signal is separated and detected as shown in Table 1. Based on the control signal thus separated and detected, the data processing method in the still image processing circuit 36 and the motion signal which is the output signal of the motion detection circuit 35 are controlled.

[0010]

[Table 1]

The mixing circuit 38 mixes the moving image signal and the still image signal for each pixel based on the above motion signal,
Alternatively, it is sent to the TCI decoding circuit 39 after being switched. In the TCI decoding circuit 39, the line-sequential / time-division multiplexed luminance signal and chrominance signal, which are the output signals of the mixing circuit 38, are TCI-decoded. The TCI-decoded luminance signal and color-difference signal are input to the D / A conversion circuit 40, converted into analog signals, and then output from the output terminal 41.

The still image processing circuit 36 performs still image processing as follows to generate a still image signal. That is, as described above, the still image signal is generated by performing the interpolation process using all the sample points of the four fields. Therefore, in order to perform such an interpolation process, it is necessary to accurately grasp the sampling phase of the sample point.

Data indicating the sampling phase is written in the control signal shown in Table 1. This data is separated and detected by the control signal separation / detection circuit 33, and the phase with respect to the previous frame and the previous field is judged based on this to obtain a good image.

Therefore, in order to obtain a good image even when performing variable speed reproduction such as so-called slow reproduction in which the tracks on the medium are reproduced in an order different from that at the time of recording, M is required.
A control signal corresponding to a video signal which is indispensable for the interpolation processing in the USE decoder is required.

In order to secure a reproduction RF signal during slow reproduction, a magnetic head having a positive azimuth angle (hereinafter referred to as + azimuth head) A ₁ and a negative azimuth angle as shown in FIG. 12 are used. A magnetic head arrangement (hereinafter referred to as “−azimuth head”) A ₂ and a pair of + azimuth head A ₄ and −azimuth head A ₃ that the magnetic head has are provided on the peripheral edge of the rotary drum 42. The signal recorded on the tape 43 in one track and one field is reproduced.

₄ by the magnetic heads A _{1 to} A _{4 having the} above structure
When slow reproduction at 1 × speed is performed, the locus of the magnetic head becomes as shown in FIG. 13A, and the reproduction RF signal is generated by the + azimuth heads A ₁ · A ₄ and −azimuth heads A ₂ · A _3. Will be picked up (Fig. 13
(B)). Then, the envelope of the reproduction RF signal at this time is as shown in FIG. Incidentally, FIG. 13 (c)
The numbers inside correspond to the corresponding fields.

The outputs of the magnetic heads A _{1 to} A ₄ are switched and output by the circuit shown in FIG. In FIG. 14, the signals output from the magnetic heads A _{1 to} A ₄ are input to the reproduction amplifiers 44 to 47, respectively. The outputs of the reproduction amplifier 44 and the reproduction amplifier 46 are
The signals are input to the input terminals 48a and 48b of the selector 48, and the outputs of the reproduction amplifier 45 and the reproduction amplifier 47 are input terminals 49a and 49b of the selector 49, respectively.
Entered in.

The frame pulse signal Fp is input to the selectors 48 and 49. In the selector 48, the input terminal 48a or 4 is selected by the frame pulse signal Fp.
8b is connected to the output terminal 48c + azimuth head A ₁
Alternatively, the output signal of the azimuth head A ₂ is selected and output from the output terminal 48c. Similarly, in the selector 49, + azimuth head A is generated by the frame pulse Fp.
The output signal of the ₃ or-azimuth head A ₄ is selected and output from the output terminal 49c.

The signal output from the selector 48 is input to the input terminal 53a of the selector 53 and the detector 5
It is input to the comparator 52 via 0. On the other hand, selector 4
The signal output from 9 is the input terminal 53b of the selector 53.
And to the comparator 52 via the detector 51. Based on the control signal output from the comparator 52, in the selector 53, the input terminal 53a or 53
b is switched and connected to the output terminal 53c, and the selected signal is output via the output terminal 54.

With the above structure, each of the magnetic heads A _{1 to} A _1
The video signal reproduced by ₄ is switched and output by comparing the magnitude of the RF signal.

[0021]

However, at this time, if switching is performed in the middle of the field of the reproduced video signal, one field at the time of 1/4 speed reproduction is composed of data of two fields. It will be.
That is, during slow reproduction, the reproduced video of one field may be composed of data of a plurality of fields having different subsampling phases. Therefore, the phase information included in the reproduction control signal cannot be associated with all reproduction video signals, and as a result, erroneous interpolation processing is performed in the subsequent decoder, resulting in a problem that image quality is significantly deteriorated. is doing.

The present invention has been made in view of the above,
The purpose is that one field of the reproduced video signal is composed of data having the same sub-sampling phase, and the phase information of the control signal is
By changing the phase information corresponding to the sub-sampling phase of the reproduced video signal, good slow reproduction is realized.

[0023]

In order to solve the above-mentioned problems, a magnetic recording / reproducing apparatus according to a first aspect of the present invention has a band-compressed signal recorded in one field in one track (for example,
In a magnetic recording / reproducing apparatus for magnetically recording / reproducing a MUSE signal), a slow reproducing head of opposite azimuth, which is provided in the vicinity of a normal reproducing head, a reproducing means for reproducing a control signal included in a video signal, and a reproducing means. A change means for changing the reproduced control signal is provided, and during slow reproduction, one field at the time of slow reproduction is composed of data of a single field and data of different sub-sampling phases is not mixed for the above normal reproduction. It is characterized in that the head and the slow reproduction head are switched in field units, and the phase information in the control signal is made to correspond to the reproduced video data.

The motion information changing means for changing the motion information contained in the control signal into a signal indicating a motion state so that the interpolation processing in the MUSE decoder becomes a complete field interpolation processing. Is preferably provided.

Further, with respect to eight kinds of phase information which are considered in advance as phase information, a ROM in which eight control signal patterns each having motion information as a signal indicating a motion state are programmed, and a phase of image data from the ROM are set. It is preferable that the control signal is provided with a reading means for reading a corresponding control signal, and the reproduced control signal is selected during normal reproduction, and the control signal read from the ROM by the reading means is selected during slow reproduction.

Further, in addition to the aspect of claim 1, a memory device for storing the reproduced control signal and a predicting means for predicting a point where the field reproduced by the slow reproduction changes are reproduced, and the control signal is reproduced. It is preferable to control the control signal written in the memory device so as to correspond to the generated video data.

At this time, the motion information in the control signal is changed to a signal indicating the motion state while keeping the control signal in the transmission form so that the interpolation process in the MUSE decoder becomes a complete field interpolation process. It is preferable to include means for changing motion information.

[0028]

According to the structure of claim 1, when the signal recorded in one track and one field is reproduced by the normal reproduction head and the slow reproduction head, the reproduced video signal is switched for each field.

At this time, the changing means changes the control signal so as to have phase information corresponding to the reproduced video signal, and adds the control signal to the reproduced video signal. That is, a reproduced video signal to which a control signal having phase information corresponding to the phase of each field of the video signal is added can be obtained.

Further, since the motion information changing means changes the motion information contained in the reproduction control signal into a signal indicating the motion state, deterioration of image quality due to non-circulation of the phase information in the reproduction control signal is avoided. .

Further, since the ROM is provided, the reproduced control signal is selected during the normal reproduction, and the control signal corresponding to the phase of the video data read from the ROM by the reading means is selected during the slow reproduction.

In addition to the structure of claim 1, the memory device and the predicting means are provided, so that the predicting means predicts a point at which the field reproduced by the slow reproduction changes during the slow reproduction, and immediately before the field changes. Then, control is performed so that the control signal is written in the memory device. Therefore, the control signal output from the memory device is changed immediately before the field changes and added to the video data, and the same control signal is output until the time immediately before the next field changes,
A control signal corresponding to the reproduced video data will be added.

In addition, the motion information changing means allows the MUS
The motion information included in the control signal is changed to a signal indicating the motion state so that the interpolation process in the E decoder is a complete field interpolation process. The deterioration of the image quality due to the fact that the phase information in the control signal does not circulate is avoided.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

The main part of the configuration example of the magnetic recording / reproducing apparatus according to this embodiment will be described below with reference to FIG.

A signal recorded on a magnetic tape (not shown) in one track and one field is reproduced by, for example, + azimuth heads 1.4 and −azimuth heads 2.3. Here, + azimuth head 1 and −azimuth head 2 are normal reproducing magnetic heads, + azimuth head 4 and −
The azimuth head 3 is a slow reproduction magnetic head. As shown in FIG. 1, the video signal reproduced by the + azimuth head 1 is input to the input terminal 9a of the selector 9 via the reproduction amplifier 5, and the video signal reproduced by the + azimuth head 4 is transmitted via the reproduction amplifier 7. Is input to the input terminal 9b of the selector 9. On the other hand, the video signal reproduced by the azimuth head 2 is transmitted through the reproduction amplifier 6 to the selector 10
The video signal reproduced by the azimuth head 3 is input to the input terminal 10a of the selector 10 via the reproduction amplifier 8.

A frame pulse signal Fp having a duty ratio of 50 is input to the selector 9, and a signal output from the output terminal 9c based on the frame pulse signal Fp is input terminal 9
The signal from a and the signal from the input terminal 9b can be switched.

Similarly, the frame pulse signal Fp is input to the selector 10, and the output signal from the output terminal 10c is switched between the signal from the input terminal 10a and the signal from the input terminal 10b.

The signal output from the selector 9 and the signal output from the selector 10 are input to the input terminal 11a and the input terminal 11b of the selector 11, respectively. The selector 11 includes a pulse signal F that changes the cycle of the frame pulse signal Fp in accordance with the slow reproduction speed ratio (1 / n).
p / n is input, and a signal switched between the signal from the input terminal 11a and the signal from the input terminal 11b according to the pulse signal Fp / n is output from the output terminal 11c. The signal output from the selector 11 is output to the output terminal 12
It is designed to be sent to a demodulator (not shown) in the subsequent stage via the.

When 1/4 speed reproduction is performed in the above configuration, the reproduction RF signals of the video signals reproduced by the + and − azimuth heads 1 to 4 are respectively shown in FIG.
As shown in (a) to (d). The reproduction RF signals are amplified by the reproduction amplifiers 5 to 8, respectively, and the reproduction RF signals from the + azimuth heads 1 and 4 are supplied to the selector 9,
The reproduction RF signal from the azimuth heads 2 and 3 is input to the selector 10. In the selectors 9 and 10, FIG.
The reproduction RF signal from each magnetic head is switched by the frame pulse signal Fp shown in FIG.
A reproduction RF signal as shown in (g) is output.

The reproduction RF signals output from the selector 9 and the selector 10 are input to the selector 11, and the selector 11 has a cycle four times as long as the frame pulse signal Fp as shown in FIG. Pulse signal F having
p / n is input. The output from the selectors 9 and 10 is switched by this pulse signal Fp / n, and
A reproduced RF signal having no field mixture as shown in (1) is output from the selector 11 and sent to the demodulator in the subsequent stage via the output terminal 12.

Next, the means for generating the control signal corresponding to the sub-sampling phase of the video signal reproduced without field mixture will be described with reference to FIGS. 3 to 8.

As shown in FIG. 3, the reproduction control signal detected by the control signal detecting circuit 15 which is the reproducing means is output to the control signal switching circuit 14 as a control signal for normal reproduction, and at the same time, the control signal decoding circuit. 16 is output.

The control signal decoding circuit 16 decodes the expanded Hamming coded reproduction control signal and sends it to the control signal rewriting circuit 17.
In the control signal rewriting circuit 17, since the phase information included in the decoded reproduction control signal is the phase information corresponding to the next field at the time of normal reproduction, the phase is calculated by predicting the next field at the time of slow reproduction from the speed of slow reproduction. The information is rewritten and the rewritten reproduction control signal is output to the control signal encoding circuit 18. In the control signal coding circuit 18, the rewritten reproduction control signal is expanded and Hamming coded and output to the control signal switching circuit 14 as a reproduction control signal at the time of slow reproduction.

In the control signal switching circuit 14,
By the normal reproduction / slow reproduction switching signal P output based on the information indicating whether the reproduction is normal reproduction or slow reproduction, in the case of normal reproduction, the reproduction control signal directly input from the control signal detection circuit 15 is delayed. In the case of reproduction, the reproduction control signal input from the control signal encoding circuit 18 is selected and output to the control signal adding circuit 13. In the control signal adding circuit 13, after the reproduction control signal is added to the reproduced video signal, it is output,
It is adapted to be sent to a subsequent circuit (not shown) via the output terminal 19.

The control signal decoding circuit 4, the control signal rewriting circuit 5 and the control signal encoding circuit 6 constitute a changing means.

In the above structure, during slow reproduction,
The normal reproduction / slow reproduction switching signal P is output to the control signal switching circuit 14. In the control signal switching circuit 14, the switching control signal P selects a playback control signal for slow playback, that is, a playback control signal input from the control signal encoding circuit 18, and outputs it to the control signal adding circuit 13. In the control signal addition circuit 13, the rewritten reproduction control signal is added to the video signal at the time of slow reproduction generated by switching for each field as described above. That is, the reproduction control signal is inserted at a predetermined position of the MUSE signal (see FIG. 9), and the MUSE signal of the transmission form is reformed.

As a result, a reproduction video signal reproduced by the normal reproduction head and the slow reproduction head without field mixture and a reproduction control signal corresponding to the reproduction video signal are followed by a MUSE decoder (not shown). Since the data is transmitted to the first side, the interpolation processing is performed at the correct phase, and as a result, a good slow reproduction image is obtained.

By the way, when a search is made for a motion picture of a control signal which is originally a still picture [1], an interpolation process using four fields is performed.

However, in the method using the circuit having the above configuration, the phase circulation is different from that in the normal reproduction, so that the image quality may deteriorate when the still image processing is performed.

Therefore, in order to solve this problem, the following measures are taken in this embodiment. That is, in the control signal rewriting circuit 17 of FIG. 3, the phase information of the control signal is rewritten, and the motion information included in the control signal is changed to the degree of motion [7], and then interpolated by the MUSE decoder. The processing is only field interpolation. As a result, the reproduced image is not affected by the deviation of the phase circulation, and a good slow reproduced image can be obtained.

Further, in the circuit shown in FIG. 3 described above, in order to obtain the control signal for slow reproduction, in addition to the circuit for rewriting the phase information, the control signal rewriting having the circuit serving as the above motion information changing means. The circuit 17 and the control signal encoding circuit 18 for encoding the rewritten signal into the transmission form again are required, which increases the circuit scale.

Therefore, in FIG. 3, an example in which the circuit scale is reduced is shown below. Members having the same functions as those shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 4, the reproduction control signal decoded by the control signal decoding circuit 16 is output to the control signal generation ROM 20 (ROM). In the control signal generation ROM 20, with respect to the eight kinds of phase information considered as the phase information included in the reproduction control signal, the motion information is set to the degree of motion [7], and the reproduction control signal pattern is expanded Hamming coded for transmission. Is pre-programmed. Further, a signal Q relating to the speed of slow reproduction is input to the control signal generation ROM 20.

In the above structure, the control signal switching circuit 1 is controlled by the switching signal P during slow reproduction.
4, the signal from the control signal generation ROM 20 is selected as the reproduction control signal.

On the other hand, in the control signal generation ROM 20, the reading means gives the speed Q of the slow reproduction and the phase information of the reproduction control signal input from the control signal decoding circuit 16 to, for example, the upper address of the ROM to reproduce the reproduction signal. The reproduction control signal corresponding to the phase information of the video signal is selected and read. Then, the read reproduction control signal is output to the control signal switching circuit 14 as a reproduction control signal for slow reproduction.

Then, the control signal switching circuit 1
The signal output from 4 is the control signal adding circuit 13
At, the signal is added to the reproduced video signal and is output to the subsequent circuit (not shown) via the output terminal 19.

Next, in slow reproduction, focusing on the fact that the reproduced fields are continuous, an embodiment in which the reproduction control signal can be changed more easily will be described with reference to FIGS. While explaining.

As shown in FIG. 5, the reproduction control signal detected by the control signal detection circuit 15 is sent to the control signal storage RAM 21 as a memory device.

Further, the control signal R is output from the control circuit 22 which is the predicting means to the control signal storage RAM 21. The control signal R permits writing to the storage RAM at the time of normal reproduction, and permits writing only at the field immediately before the field to be reproduced changes during slow reproduction. Control signal storage RAM 21
The signal output from is input to the control signal adding circuit 13.

In the above structure, during normal reproduction, the control circuit 22 outputs a write control signal R as shown in FIG. 6A, that is, a signal that always permits writing, to the control signal storage RAM 21. Therefore, the reproduction control signal (FIG. 6 (c)) output from the control signal detection circuit 15 is sequentially written in the storage RAM, and the output from the control signal storage RAM 21 is as shown in FIG. 6 (d). As a result, the control signal adding circuit 13 adds a reproduction control signal corresponding to the reproduced video signal (FIG. 6B).

On the other hand, when the slow reproduction command is input to the control circuit 22 during the slow reproduction, the control circuit 22 outputs the command shown in FIG.
The control signal R shown in FIG.
21 is output. On the basis of this control signal R, the reproduction control signal (FIG. 7 (c)) output from the control signal detection circuit 15 is output only in the field immediately before the field of the reproduction video signal (FIG. 7 (b)) changes. Written to storage RAM.

As a result, the control signal storage RAM2
The reproduction control signal output from 1 to the control signal adding circuit 13 is as shown in FIG. Therefore, the reproduction control signal corresponding to the image to be reproduced is selected, and in the control signal adding circuit 13,
The MUSE signal in transmission form is reshaped.

In the present embodiment, the control signal decoding circuit 16 for decoding the control signal is unnecessary as compared with the method using the control signal generating ROM 20 described above, so that the reproduction control corresponding to the reproduced video signal can be performed more easily. The signal is selected, and the circuit scale can be further reduced.

Further, as described above, FIG. 8 shows the case where the motion information in the reproduction control signal is changed to the degree [7] so that the deviation of the phase circulation during slow reproduction does not affect the reproduced image. As described above, the control signal rewriting circuit 23 (motion information changing means) is controlled by the control signal storage RA.
It can be provided in the subsequent stage of M21 and can be changed as it is in the transmission form of the MUSE signal. Therefore, a circuit for decoding the reproduction control signal is unnecessary and the circuit scale can be reduced.

[0066]

According to the magnetic recording / reproducing apparatus of the present invention,
As described above, the slow reproduction heads of mutually opposite azimuths provided in the vicinity of the normal reproduction head, the reproduction means for reproducing the control signal included in the video signal, and the change for changing the control signal reproduced by the reproduction means Means for switching the normal reproduction head and the slow reproduction head so that one field at the time of slow reproduction is composed of data of a single field and data of different sub-sampling phases do not coexist during slow reproduction. Is performed in field units, and the phase information in the control signal is made to correspond to the reproduced video data.

Therefore, the video signal reproduced by the normal reproduction head and the slow reproduction head during the slow reproduction ensures a reproduction RF signal sufficient for demodulation, and
Since it is switched for each field, a plurality of phase information will not be mixed and a control signal having phase information corresponding to the reproduced video signal can be obtained at the time of slow reproduction, so that in the subsequent decoder. Since the interpolation processing is performed in the correct phase, a good slow reproduction image can be obtained.

Further, by providing the motion information changing means for changing the motion information contained in the control signal into a signal indicating the motion state, it is possible to avoid the deterioration of the image quality due to the fact that the phase information in the control signal does not circulate, and Since the processing by the decoder can be performed in the field, the effect that a good slow reproduction image can be obtained is also obtained.

In addition to the above configuration, the magnetic recording / reproducing apparatus according to the third aspect of the present invention has eight types of phase information, which are preliminarily considered as phase information, in which eight pieces of motion information are used as signals indicating a motion state. A ROM programmed with a control signal pattern and a reading means for reading a control signal corresponding to the phase of the video data from the ROM are provided. The reproduced control signal is selected during normal reproduction, and the reading means reads out the ROM from the ROM during slow reproduction. The read control signal is selected.

Therefore, in addition to the above effects, there is an effect that the circuit scale can be reduced.

In addition to the structure of claim 1, the magnetic recording / reproducing apparatus of claim 4 predicts a point at which a field for reproducing a control signal and a memory device for storing a reproduced control signal change. A predicting means is provided, and the control signal written in the memory device is controlled so that the control signal corresponds to the reproduced video data. Therefore, since the control signal having the phase information corresponding to the video data reproduced by the normal reproduction head and the slow reproduction head can be obtained during the slow reproduction, the subsequent decoder performs the interpolation processing with the correct phase. In addition to the effect that a good slow reproduction image can be obtained, a decoding circuit and an encoding circuit for the reproduction control signal are not required, and the circuit scale can be reduced, so that the magnetic recording / reproducing apparatus for home use is required to be downsized. The effect that it can be applied sufficiently to Further, by providing the motion information changing means for changing the motion information in the control signal into a signal indicating the motion state, the interpolation processing in the decoder can be a complete field interpolation processing, The effect that a good slow reproduction image can be obtained is also obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is a frame pulse signal and R in the configuration of FIG.
It is explanatory drawing which shows the output of F signal.

FIG. 3 is a block diagram showing a circuit for rewriting a control signal of the magnetic recording / reproducing apparatus of the present invention.

FIG. 4 is a block diagram showing another configuration of the circuit of FIG.

FIG. 5 is a block diagram showing a circuit for changing a control signal of another magnetic recording / reproducing apparatus of the present invention.

FIG. 6 is an explanatory diagram showing an operation during normal reproduction in the configuration of FIG.

FIG. 7 is an explanatory diagram showing an operation during slow playback in the configuration of FIG.

8 is a block diagram showing a main configuration of a magnetic recording / reproducing apparatus in which a control signal rewriting circuit is added to the configuration of FIG.

FIG. 9 is an explanatory diagram showing a structure of a MUSE signal.

10 is an explanatory diagram of a sampling pattern showing a sampling phase in a video portion of the MUSE signal of FIG.

FIG. 11 is a block diagram showing a main configuration of a conventional MUSE decoder.

FIG. 12 is an explanatory diagram showing an arrangement of magnetic heads for reproducing signals recorded in one track and one field.

FIG. 13 is an explanatory diagram illustrating a case where a quarter speed reproduction is performed using the magnetic head of FIG.

FIG. 14 is a block diagram showing a circuit for obtaining a conventional reproduction RF signal.

[Explanation of symbols]

1 + Azimuth head (normal reproducing head) 2-Azimuth head (normal reproducing head) 3-Azimuth head (slow reproducing head) 4 + Azimuth head (slow reproducing head) 15 CTL signal detection circuit (reproducing means) 16 CTL signal decoding circuit (Changing means) 17 CTL signal rewriting circuit (changing means, motion information changing means) 18 CTL signal coding circuit (changing means) 20 CTL signal generation ROM (ROM) 21 CTL signal storage RAM (memory device) 22 Control circuit (prediction) 23) CTL signal rewriting circuit (motion information changing means)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michiyuki Sugino             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Within Yap Co., Ltd.

Claims (5)

[Claims] 1. In order to compress a band, in the case of a still image, information of one screen is sampled and sampling phases of adjacent fields are sequentially shifted to make one cycle by n fields (n is an integer of 2 or more) to complete one screen. Information is formed by n fields, and in the case of a moving image, 1 screen of information is sampled and
This is a device for recording / reproducing one field on one track by a rotary head, which is formed by fields and sequentially shifts the sampling phase of adjacent fields, and superimposes a control signal indicating the state of a still image or a moving image on each track. A slow reproduction head of opposite azimuth provided near the head for reproduction, reproduction means for reproducing a control signal included in the video signal, and change means for changing the control signal reproduced by the reproduction means, During slow reproduction, switching between the normal reproduction head and the slow reproduction head is performed in field units so that one field during slow reproduction is composed of a single field of data and data of different sub-sampling phases do not mix. , Video data that reproduces the phase information in the control signal. A magnetic recording / reproducing apparatus characterized by being compatible with a computer. 2. A motion information changing means for changing the motion information in the control signal into a signal indicating a motion state so that the interpolation processing in the MUSE decoder becomes a complete field interpolation processing. The magnetic recording / reproducing apparatus according to claim 1. 3. A ROM in which eight control signal patterns each of which has motion information as a signal indicating a motion state are programmed with respect to eight kinds of phase information which are considered in advance as phase information, and a phase of video data from the ROM. A read-out means for reading out a corresponding control signal is provided, and the reproduced control signal is selected during normal reproduction, and the ROM is read out by the read-out means during slow reproduction.
3. The magnetic recording / reproducing apparatus according to claim 2, wherein the control signal read from is selected. 4. A memory device for storing a reproduced control signal, and a prediction means for predicting a point where a field reproduced by slow reproduction changes, so that the control signal corresponds to the reproduced video data. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein a control signal written in the memory device is controlled. 5. A motion for changing motion information in a control signal into a signal indicating a motion state while keeping the control signal in the transmission form so that the interpolation process in the MUSE decoder becomes a complete field interpolation process. The magnetic recording / reproducing apparatus according to claim 4, further comprising information changing means.